What can we say about the value of the P-value?

Nov 29th, 2014

KateS

Category:

Statistics

Price: $5 USD

Question description

A lab scientist is interested in whether lab rats that grow
up alone grow as large as lab rats that grow up with other rats around them to
play with. He randomly selects 10 young rats with approximately the same age
and size. Five of these will spend the next four monthsalone and the other five
rats will each have three other rats to play with during the same time. After
four months, the scientist measures the abdomen circumference of all the rats
(in mm). The results are shown below:

Alone
group (#1)

110

123

113

103

120

Play
group (#2)

119

125

131

128

136

The sample means and sample standard deviations are

xbar1= 113.8 and s1 =
7.98, xbar2= 127.8 and s2 =
6.38

The
sample standard deviations are fairly close in value. Based on these estimates,
it is reasonable to assume that the two population variances are equal?